Two-dimensional simulation of flow and platelet dynamics in the hinge region of a mechanical heart valve

V Govindarajan; H S Udaykumar; K B Chandran

doi:10.1115/1.3005158

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Two-dimensional simulation of flow and platelet dynamics in the hinge region of a mechanical heart valve

Journal article

Peer reviewed

Two-dimensional simulation of flow and platelet dynamics in the hinge region of a mechanical heart valve

V Govindarajan, H S Udaykumar and K B Chandran

Journal of biomechanical engineering, Vol.131(3), pp.031002-031002 (12 )

03/2009

DOI: 10.1115/1.3005158

PMCID: PMC2744151

PMID: 19154061

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Abstract

The hinge region of a mechanical bileaflet valve is implicated in blood damage and initiation of thrombus formation. Detailed fluid dynamic analysis in the complex geometry of the hinge region during the closing phase of the bileaflet valve is the focus of this study to understand the effect of fluid-induced stresses on the activation of platelets. A fixed-grid Cartesian mesh flow solver is used to simulate the blood flow through a two-dimensional geometry of the hinge region of a bileaflet mechanical valve. Use of local mesh refinement algorithm provides mesh adaptation based on the gradients of flow in the constricted geometry of the hinge. Leaflet motion is specified from the fluid-structure interaction analysis of the leaflet dynamics during the closing phase from a previous study, which focused on the fluid mechanics at the gap between the leaflet edges and the valve housing. A Lagrangian particle tracking method is used to model and track the platelets and to compute the magnitude of the shear stress on the platelets as they pass through the hinge region. Results show that there is a boundary layer separation in the gaps between the leaflet ear and the constricted hinge geometry. Separated shear layers roll up into vortical structures that lead to high residence times combined with exposure to high-shear stresses for particles in the hinge region. Particles are preferentially entrained into this recirculation zone, presenting the possibility of platelet activation, aggregation, and initiation of thrombi.

Computational Biology - methods

Shear Strength

Pulsatile Flow

Models, Cardiovascular

Humans

Heart Valve Prosthesis - adverse effects

Stress, Mechanical

Blood Platelets - physiology

Hemorheology

Prosthesis Design

Algorithms

Platelet Activation

Computer Simulation

Blood Flow Velocity

Hemodynamics

Details

Title: Subtitle: Two-dimensional simulation of flow and platelet dynamics in the hinge region of a mechanical heart valve
Creators: V Govindarajan - Department of Biomedical Engineering, College of Engineering, The University of lowa, 1402 SC, lowa City, IA 52242, USA
H S Udaykumar
K B Chandran
Resource Type: Journal article
Publication Details: Journal of biomechanical engineering, Vol.131(3), pp.031002-031002 (12 )
DOI: 10.1115/1.3005158
PMID: 19154061
PMCID: PMC2744151
NLM abbreviation: J Biomech Eng
ISSN: 0148-0731
eISSN: 1528-8951
Publisher: ASME International; United States
Grant note: R01 HL071814 / NHLBI NIH HHS R56 HL071814 / NHLBI NIH HHS HL 071814 / NHLBI NIH HHS R01 HL071814-04 / NHLBI NIH HHS
Language: English
Date published: 03/2009
Academic Unit: Roy J. Carver Department of Biomedical Engineering; Injury Prevention Research Center; Mechanical Engineering
Record Identifier: 9984064215602771

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